|
|
|
Carmi Orenstein
M.P.H., Editor
Ribbon readers are aware of the twice-yearly Regional Cancer and Environment Forums that BCERF facilitates around New York State (NYS); we publish summaries of each one in this newsletter. Many of you - even out-of-state readers - have participated in these events. In this issue, we are featuring an expanded overview of the most recent Forum, including an interview with one of the speakers, Nellie Brown. We place special emphasis on the panel discussion featured at the Forum.
Over 50 participants gathered for an interactive day addressing issues related to occupational cancers in women, exposure to mammary carcinogens, and emerging research on the flame retardants, PBDEs (polybrominated diphenyl ethers). These issues were discussed at BCERF's fall 2005 Regional Cancer and Environment Forum, held in Albany on September 30. Presentations and discussion created an opportunity to share information and address the critical question: where do we go from here on issues of emerging chemical hazards?
When the Forum takes place in Albany, BCERF strives to present an opportunity for elected representatives and their staffs, as well as state agency professionals, to interact with other scientists, activists and members of the public on these topics. There was excellent participation from the many branches of the NYS Department of Health, as well as from legislative staff. Other participants included representatives of the medical community, several breast cancer advocacy groups, Cornell Cooperative Extension and other not-for-profit organizations, and the American Chemistry Council.
The morning sessions addressed an area increasingly important to BCERF's translational research work: occupational exposures to chemical carcinogens. Dr. Suzanne Snedeker drew on her work investigating the state of the research on female occupational cancers for her talk, Women, the Workplace, and Cancer Risk. Her overview of the history of what is known about women and occupational cancer risk displayed both important early observations - such as the discovery of the increased risk of breast cancer in nuns in the 1700s - as well the long-term lack of inclusion women in occupational cancer studies. Not only were women often not included in studies that did take place historically, but specifically female cancers, as well as women's different or increased vulnerabilities to exposure to carcinogens, have all been understudied.
Since the mid 1990s more data is accumulating which suggests that women's risk of breast cancer is increased in some workplaces. Worldwide epidemiologic research is showing an increased risk in certain professions, and with certain chemical exposures (laboratory research has also identified mammary carcinogens; more below). Based on these observational studies, Dr. Snedeker presented a list of occupations that need further evaluation (see box). Fortunately, there are also several large epidemiologic studies taking place currently that are addressing some populations at increased risk, such as the Sister Study (which has an occupational component) (see http://www.sisterstudy.org
and Volume 9, No. 4 issue of The Ribbon), the California Teachers Study (see http://www.calteacherstudy.org), and others.
The National Toxicology Program (NTP) identified 42 mammary carcinogens in cancer bioassays, many of which exist in contemporary workplaces. BCERF is working with this list in a project entitled Chemicals, the Workplace and Cancer Risk. This work grew out of the EnviroChem and Cancer Database (see http://envirocancer.cornell.edu/eccd/ and Volume 9 Number 3 issue of The Ribbon). In the September Forum, participants were able to hear the unique work being done by Dr. Snedeker and colleague Nellie Brown in bringing to light the many possibilities for exposure to these mammary carcinogens. Ms. Brown's presentation, Mammary Carcinogens: Scenarios for Exposure, demonstrated the workplace, home and broader community and environmental possibilities for exposure to NTP mammary carcinogens such as benzene, 1,3-butadiene, and 2,4-toluendiamine. Ms. Brown has developed a "cradle-to-cradle protocol" for examining the real-life scenarios for exposure in the workplace, based on the chemical's origin, its transport, all intended or unintended uses of it, and its disposal. She is also compiling information on ways consumers may be exposed to these carcinogens. See the accompanying interview with Ms. Brown for a fuller picture of the experience she brings to this work and the data being compiled.
BCERF strives to communicate the latest information on emerging contaminants. There is growing evidence that the flame retardants PBDEs are bioaccumulating in humans and wildlife. PBDEs are structurally similar to polychlorinated biphenyls (PCBs). Research in animal models indicates PBDEs may have some of the same health effects as PCBs, which are environmental estrogens and have been shown to interfere with thyroid function and learning development. Certain types of PBDEs are suspected of linkages with a variety of long-term health concerns, such as hormone disruption, possible carcinogenicity, and neurological, reproductive, and developmental effects (see box).
The three most common commercial mixtures of PBDEs are penta-, octa- and deca-BDE, named according to the number and arrangement of the bromine atoms. (See the table on facing page for composition and uses of these commercial mixes.) PBDEs have been phased out by some European countries; some types are being voluntarily phased out by manufacturers in the United States. NYS has passed legislation to phase out two of the commercial formulations, penta-BDE and octa-BDE. The use of deca-BDE is being reviewed to assess health effects of the deca form (deca-BDE has 10 bromine atoms), and whether it can degrade to other forms (congeners) of PBDEs that have fewer bromine atoms. While researchers believed that deca-BDE was poorly absorbed because of its bulky structure and therefore did not bioaccumulate in tissues, new research has detected deca-PBDE in bird eggs. Some types of fish appear to be able to break deca-BDE down to congeners that have fewer bromine atoms, have the capacity to bioaccumulate, and may travel up the food chain.
In the afternoon of the Forum, participants welcomed Dr. Kurunthachalam Kannan of the Wadsworth Center at the NYS Department of Health and the Department of Environmental Health Sciences at SUNY Albany. His talk was entitled Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs) in Human Adipose Tissue from New York. Dr. Kannan shared unique data that his team collected which documents levels of PBDEs and PCBs in fat samples of New York City residents (Johnson-Restrepo, et al., 2005) This study documented the highest adipose tissue levels of PBDEs of any human study published to date. Average PBDE concentrations from this study were 10- to 100-times greater than those reported for European countries.
There are multiple ways that people can be exposed to PBDEs; for example, since it is present in so many consumer products, there is the possibility of breathing dust from degradation. These materials are heavily present in the environment and can also be taken up through the food chain (see box on Cornell work addressing the degradation of PBDEs in the environment). Dr. Kannan's research suggests there is a high degree variation in human exposures associated with specific occupational and environmental settings, and his research team recommends further research to identify the sources of exposure and to assess the adverse effects on human health. The afternoon panel provided an opportunity to at least briefly discuss the many public health questions brought up by the kind of data Dr. Kannan shared.
The panel reflected the diversity of participants in the day's Forum: Dr. Suzanne Snedeker of BCERF; Kathy Curtis of Citizens' Environmental Coalition; Bob Campbell of Great Lakes Chemical Corporation; Margaret Roberts of Capital Region Action Against Breast Cancer (CRAAB!); Beth Meer from the office of Assemblyman Thomas DiNapoli, and; Debbie Peck Kelleher from the office of Senator Carl Marcellino. The panel was moderated by BCERF's Director, Dr. Rodney Page. Panel members represented their respective constituencies on the question Emerging Chemical Concerns: Where Do We Go From Here?
Bob Campbell began the discussion, commenting that flame retardants save lives everyday and that caution must be exercised when promoting product substitution; "the substitute needs to actually reduce risk," and, "the replacement might be worse." When Hope Nemiroff offered the question, "why are we always playing catch up, after chemicals are already out there?" a conversation ensued about the need for a model other than the typical risk assessment/regulatory model.
Beth Meer offered ideas along those lines. Ms. Meer said that too few chemicals are being tested with the current model (the extremely high cost of testing chemicals came up several times throughout the panel discussion), and there are several persistent challenges with current scientific models: for example, extrapolating from animal studies. She cited several examples of programs that are developing broad-reaching approaches to substitution with safer alternatives, such as the Toxics Use Reduction Institute (TURI) at the University of Massachusetts Lowell (http://www.turi.org/) and the Center for Integrated Manufacturing Studies (CIMS) at the Rochester Institute of Technology (http://www.cims.rit.edu)
Dr. Snedeker provided some background on the scientific community's response to PBDEs. She described the enormous number of papers that are currently being published on PBDEs, and the escalating levels of these chemicals in both wildlife and humans that this work documents. She expanded upon Dr. Kannan's comments regarding health concerns that these levels raise, and noted that the CDC's biomonitoring efforts, as part of its Environmental Public Health Tracking Program (see Volume 10, Number 3 issue of The Ribbon) will be adding PBDEs to its program beginning in 2007.
Speaking for the cancer survivor community, Margaret Roberts reiterated that it will take decades to show proof of harm and that a precautionary approach is warranted as soon as a body of evidence indicates an exposure is harmful. She outlined and expressed support for the several bills developed by Congressman DiNapoli and Senator Marcellino and colleagues that would expand precautionary policies on the NYS level: the Public Health Protection Act (which would establish criteria to guide a precautionary policy; http://assembly.state.ny.us/leg/?bn=A07256), the Sustainable and Safe Procurement Act (http://assembly.state.ny.us/leg/?bn=A07257), and the Environmental Public Health Tracking Act (http://assembly.state.ny.us/leg/?bn=A00969). (Web addresses in parentheses lead to NYS Assembly versions of the bill; you can also search Senate versions of these and other bills on the Assembly's bill search page: http://assembly.state.ny.us/leg/)
Kathy Curtis cited a very recent report from the advocacy organization Illinois PIRG, entitled "Body of Evidence II: Latest Science on the Dangers of Deca-BDE in Consumer Products" (http://www.illinoispirg.org/IL.asp?id2=19439). Body of Evidence II updates the first Body of Evidence report released in February of 2004, and summarizes research results from the past year, in areas such as measurement of indoor levels of deca-BDE. Kathy also explained that there are viable alternatives that meet the highest flame retardency standards and do not increase cost.
Debbie Peck Kelleher informed the group of a task force formed by the legislature that will address issues of deca-BDE, although it has not yet convened, and that Senator Marcellino is looking into a program to recycle computers, which would then keep more of these substances out of landfills. The group was very interested in innovative policies, such as the one mentioned by Kathy Curtis in which New York City is considering a policy requiring computer manufacturers to take back used computers. Thinking about solving chemical use and exposure problems in new ways was clearly a priority for all panel members. As Beth Meer expressed, "we need a sustainability revolution."
BCERF will continue this panel feature in future Forums and thanks all participants for their contributions to this valuable day.
Program on Breast Cancer and Environmental Risk Factors
Cornell University, College of Veterinary Medicine
Vet Box 31, Ithaca, NY 14853-6401
We comply with the HONcode standard for
trustworthy health information: Verify here.